[Flyndaran]

Businessmen make horrible faux pas all the time when dealing with foreign earth cultures. And we have loads of information to check as well as being exceptionally similar, genetically.
Traveller has loads of not quite humans leading to an extreme version of the expression, "England and America are two nations divided by a common language."
Some, to even quite a bit of, information can lead to more severe mistakes than acknowledging you know nothing and walking on eggshells scrutinizing every action and word. Foreigners are expected to screw up, but if you seem to know the language and culture, then obviously, what you did was completely intentional.

That could be an interesting style. A character that knows the culture and language fluently, but creates the image of the bumbling foreigner to gain advantage and access.